Electric clock.



No. 670,634 Patented Mar. 26, IBM. F. L. GREGORY.

ELECTRIC CLOCK.

. (Application filed Mar. 2, 1900. (No Model) -2 Sheets-Sheet L J '1' 3'4 f I I l I Witnesses: E [720622 6021- K IIH J I mm. ,,"r---"----"/""'fieafi. Gregory 7? I By fez; Jtlozvzqy, I

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F. L.- GREGORY.

ELECTRIC CLOCK.

(Application filed Mar. 2, 1900.)

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UNITED STATES PATENT Orinoco FRED Ii. GREGORY, OF CHICAGO, ILLINOIS,ASSIGNOR TO THE SEMPIRE CLOCK COMPANY, OF SAME PLACE.

ELECTRIC CLOCK.

SPECIFICATION forming part of Letters Patent No. 670,634, dated March26, 1901.

Application filed March 2, 1900. Serial No, 7,046. (No model.)

To all whom it may concern.-

Be it known that I, FRED L. GREGORY,,a citizen of the United States,residing in Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Synchronizing Devicesfor Timepieces, of which the following is a specification.

This invention relates to a synchronizing device for timepieces; and ithas for its main object the provision of an improved synchronizingdevice for shifting the hands of a timepiece to a predetermined positionat a predetermined time in order to set such hands to indicate the exacttime, the setting of such hands being usually controlled by an electriccircuit governed either by a master-timepiece or by a standardtime-circuit controlled in any well-known manner.

In the preferred embodiment my invention will be applied in such amanner that both the seconds-hand and the minute-hand will be controlleddirectly, and as the hour-hand will usually be mounted in the ordinarymanner-that is to say, by gearing it to the min- 'ute-handthesynchronizing action may extend to all three of the hands generally usedto indicate the time. WVhen my invention is so applied as to controldirectly both the seconds and the minute hands, it will be evident thatthese should be set in the predetermined position synchronously, andthis position will usually be that which indicates the hour of noon.

As a timepiece will sometimes be slow and sometimes fast, it isnecessary in practice to provide means for setting the hand forward tothe predetermined position or back to such position, as the case may be.For this reason the setting device will preferably be a duplex one-thatis to say, it will have two members or working faces, one of whichshould coact with one side of the member to be set and the other withthe other side of said settable member. Hence one such setting member orface will be effective for shifting the settable member back if it ismoving too rapidly, while the other will be effective for setting itahead if it is moving too slowly. Such a duplex setting device willpreferably be employed in connection with each of the two hands justmentionedviz., the seconds-hand and the minute-hand. lVhen properlyconstructed, it will be evident that these duplex setting devices mayserve as means for centering their respective settable members or handsin the predetermined position,and an important feature of the presentinvention is the provision of means for centering the hand in suchpredetermined position to show the corrected time, regardless of whetherthe mechanism has been running fast or slowly.

The setting members for the minute and seconds hands will be controlledby and may be carried by and move with the armature of an electromagnetplaced in a circuit controlled by some standard time-circuit ormaster-timepiece for regulating the time indicated by a secondarytimepiece or timepieces, and this armature will preferably be anoscillatory one pivoted between the poles of a horseshoe-electromagnetin order to control the operation of the synchronizing device mostpositively and provide for a considerable movement of the setting memberabout its axis.

In the drawings accompanying this specification and forming tart of thepresent application, Figure l is a front elevation of a timepieceembodying my improved synchronizing device. Fig. 2 is a sectional endelevation of the upper portion of the same and illustrates the positionsassumed by the parts just before the synchronizing device becomeseffective. Fig. 3 is a sectional end elevation of a portion of themechanism, illustrating the positions of the parts when thesynchronizing device is operated. Figs. 4: and 5 are detail sectionalfront elevations of the synchronizing device, the positions of the partscorresponding, respectively, to those shown in Figs. 2 and 3; and Fig. 6is a perspective view of two setting members of the synchronizer.

Similar characters designate like parts in the different figures of thedrawings.

My synchronizing device maybe employed in connection with many differentkinds of timepieces and is not limited in its application to any oneparticular type, such as that shown. Although I have illustrated myimproved synchronizing device in connection with an electric clocksubstantially of the construction shown in my prior patent, No.

535,370, granted April 9, 1895, this particular type of mechanism ismerely shown for the purpose of illustrating one application of myinvention to clockwork. In the construction shown the clock will havethe usual front and back plates, such as 2 and 3, connected in theordinary manner by pillars and having suit-able journal-openings thereinto receive the ends of the spindles or arbors which carry l the severalhands and the other rotary parts of the time-train. Here the arbor orspindle which carries the minute-hand is designated by 5, and theminute-hand itself by m, said hand being supported in this case formovement in unison with said spindle. The shaft 5 and the minute-handmcarried. therebyare driven by a spur-gear 6, which meshes with acorresponding spur-gear 7, secured to the main driving-shaft 8, whichshaft derives its movements in this case from a weighted lever, such as9, loosely supported on said shaft and having a spring-pressed pawl 10,which engages the teeth of a ratchet-wheel 12, also secured to saidshaft, the weight in descending turning said ratchet-wheel and shaft andalso the gear-wheels 7 and 6 to drive the minute-hand. This lever 9, asjust stated, turns the wheels of the clock-train duringits descendingmovement; but at a predetermined point in its descent it should beraised again, and in order to effect this result I prefer to make use ofan electromagnet, which will be energized at the proper point in thedescending movement of the lever and will serve to raise the weight. Inthis case such an eleetromagnet is illustrated at E and is preferably ofthe horseshoe type, having an armature 13 pivoted between its ends andalso between the poles of the electromagnet. In this case the weightedlever 9 is secured to the armature 13 for movement in unison therewith,and both of the parts are loosely mounted on the shaft 8. The lever 9also has a short arm 9, from which projects a pin or finger 9, which ata predetermined point in its movement is intended to strikea detent-pawl15 and release the same from engagement with a counter-weightedcircuitmaker 16, with which the pawl normally engages. This pawl will bereleased when the weighted lever reaches the limit of its downwardmovement, and thereupon contact-point 16 on the contact-maker 16 willmake e11- gagement with a contact-arm 17 of any suit able constructionand close a circuit to a source of energy, such as the battery I),through the conductor 20, the coils of the electromagnet, conductor 21,the battery I), the conductor 22, the clock-frame, and the contact-point16, whereupon the electromagnet E will be energized and the armature 13oscillated to raise the weighted lever 9. Just before said lever reachesthe limit of its upward movement the finger 9 will strike acorresponding fingerlti on the circuit-maker 16 and shift the latter tobreak the contact with the arm 17, and thus prevent waste of thecurrent, the pawl 15 being at this time in contact with the detent faceor notch 10 of said contact-maker. Thus the weight of the lever 9 willbe continuously and regularly exerted to drive the time-train at auniform rate of speed.

A pinion moving in unison with the hand on and designated herein by (3drives,tln'ough a gear 25 and a pinion 26, a gear (3", concentric withand of the same size as the gear (3, this gear 6 being secured to thesleeve 27, which carries the hour-hand h. It should be understood thatthe gear (3 only moves in uni son with the shaft 5 when thesynchronizing device is ineffective and that said shaft is frietionallydriven, it being supported in this case in a split friction-sleeve 5,the friction between theshaft 5 and the sleeve 5, to the latter of whichsaid gear 6 is secured, being overcome when the hand is set by thesynchronizing device.

From the spur-gear 6 motion may be transmitted to the seeondshand and anescapement in a manner which is well understood, a largetransmitting-gear 6, moving in unison with the gear 6, being shownherein for this purpose. This gear (5 drives a pinion 31 on a spindle30, carrying another large transmitting-gear 32, meshing with a pinion 31- on a shaft or spindle 33, which carries the secondshand 5. Here saidseconds-hand is secured directly to this shaft 33, and the inion ismounted thereon so that the shaft 33 will be frietionally driven. In theconstruction shown an escapenient-wheel 35 is secured to this pinion,and a frictionally-driven connection between the shaft and the escapement-wheel is obtained by securing to the ratehetwvheel a light spring,such as 36, the free end of which works in and presses against a groovedcollar 33, fast on the shaft, the usual escapement 3U eoacting with theescapement-wheel.

It will be noticed that the principal difference between the devicesjust described and those which are well known in the art is that theshafts 5 and are frictionally driven by the time-train instead of beingpositively driven thereby at all times. Hence when it is necessary toset either the minute-hand or the seconds-hand the shaft 5 or the shaft33, as the case may be, may be turned relatively to its immediatedriving member without disturbing other parts of the time-train.

As before stated, I prefer to employ a synchronizing device which eoactsboth with the min ute-hand and the seconds-hand for the purpose ofsetting said hands synchronously to a predetermined position, and thesynchronizing device which is illustrated herein is so shown. In thepreferred construction it embodies at least two settable members and atleast two setting members, one settable mem bercontrolling the settingof the seconds-hand and another settable member controlling the settingof the minute-hand, while the setting members will operate in asubstantially similar manner, one coacting with the secondshand-settingelement and another with the minute-hand-setting element. Preferably thesettable element for the seconds-hand will be an arm, such as 33, fixedto the shaft 83, and hence movable in unison with the seconds-hand s,andin a like manner the settable member controlling the minute-hand maybe fixed to the shaft 5, said settable member being indicated herein by5 and being a rockarm similar to that shown at 33".

Any suitable means may be employed for actuating the setting member ormembers of the synchronizing device; but I prefer to make use of anelectromagnet, such E, substantially similar to that shown at E, andalso having an armature, such as 40, which is oscillatory about an axisbetween the poles of the electromagnet E, which, it will be seen, is ofthe horseshoe type. This electromagnet, it. should be understood, willbe included in a circuit containing a source of energy, such as abattery I), and also a circuit-making device controlled by themaster-timepiece or standard time-circuit, the circuit-controller havingin this case a rotary member 41, carryinga contact-point 41 cooperativewith a fixed contact-arm 42 These parts will usually be so arranged asto make contact between the points 41 and 42 exactly and only at thehour of noon each day.

When the electromagnet E is energized, the armature thereof will ofcourse be oscillated, and this movement of such armature may serve asthe means for imparting movement to the settable members 33 and 5 to setthe seconds-hand s and the minutehand m to the predetermined position toindicate the correct time. The setting members of the synchronizingdevice may be controlled by said armature 40 in any desired manner; butI prefer to mount them so that at least one element of each settingdevice will move directly with the armature, one member of each settingdevice of the synchronizer being in this case secured to the shaft orsleeve which carries said armature.

It has been stated hereinbefore that each of the setting members isintended to be so constructed as to be capable of shifting in eitherdirection the hand controlled therebythat is, it may serve to move thehand forward or backward, according as the timepiece is running slowlyor fast. For this reason I make use of what is essentially a duplexsetting device for each of these hands, the setting device controllingthe arm 33 being preferably a cam, such as 0, carried by an arm 41,while the setting device controlling the minute-hand embodies severalseparate elements, one of which is a rock arm or finger 42, movable inunison with the armature 40 and the arm 41. The cam c is preferably acrown-cam oscillatory about an axis transverse and in this caseperpendicular to that of the arm 33, and said cam when in its normalposition will be disposed at a considerable angle to such arm. I employa crown-cam which straddles the shaft 33 in order that the center ofmovement of the arm 33 may at all times be within the working field ofthe cam-faces. This crown-cam has in this case a pair of separated camfaces, (designated herein by and 45, re spect-ively,) which extendtoward each other and may be separated by a space, such as 45, whichforms a centering-space for receiving the arm 33, which, it should beunderstood, will preferably have a thin edge or knife-edge. In order toovercome the friction exerted by the spring 36 when the arm 33 is to bemoved very far, the cam-faces will preferably commence at the point 45'opposite the space 45 and diverge abruptly from each other, only one ofthese faces of course being effective at one time, the face which iseffective being determined by the position of the arm 33". When the camcis swung from the position shown in Figs. 2 and 4 to that illustratedin Figs. 3 and 5, the arm 33" will ride down the cam-face 45 and will becentered momentarily between the opposing walls of the space 45", thecam of course withdrawing practically instantaneously, owing to thedeenergization of the electromagnet E. At the same time that the cam cis swung in the manner just described the rock arm or finger 42 is alsooscillated. This arm may control the movements of the arm 5 in anydesired manner, but preferably will work in the bifurcated ends of apairof angle-levers, such as and 50, which normally will be in theposition shown in Figs. 2 and 4, but which when the arm 42 is raisedwill close upon the arm 5 at opposite sides thereof, and one or theother of these angle-levers will shift such arm to the predeterminedposition and center it there, this arm 5", with its hand m, also movingat this time in opposition to the friction normally exerted between theshaft 5 and the sleeve 5 for rotating such shaft. The angle-levers 50and 50 are in the nature of intermediates for transmitting the movementof the arm 42 to the arm 5, and the centeringpoint of these angle-leversmaybe determined by means of a suitable stop, which in this case may bethe shaft 30, straddled by such levers when the latter are closed. Theseangle-levers in the present case are pivoted on the inner wall of theface-plate 2, as is clearly shown, and the arm 5 is secured directly tothe shaft 5.

From the foregoing description it will be evident that when the mastertime-circuit is closed by engagement of the moving contact 41 with thecontact-arm 42 the electromagnet E will be energized and the armature 40thereof swung to the position shown in Figs. 3 and 5 and that thereuponthe rock-arms 33 and 5", and with them the hands 8 and m, (and hence thehand 7a,) will be set in the predetermined position synchronously,whereupon contact will be broken practically instantaneously at 41 and42 and the setting ICO in, a predetermined position in opposition tosuch friction; a horsesl1oe-eleotromagnet having an armature secured toan armature-shaft journaled between, and oscillatory in the plane of,thepoles thereof; and a pair of setting members both secured to saidarmatureshaft and one controlling the settable member for theseconds-hand and the other controlling said levers.

FRED L. GREGORY.

Witnesses:

J. B. ADAMS, HARLEY D. Hoovnn.

